The nation's largest dentist group now says gum can be fine for you, on condition that it is sugar-free.

The American Dental Association said that it has awarded its seal of acceptance to Wrigley sugar-free gums Orbit, Extra and Eclipse, based on studies funded at least partly by the maker of Wrigley gums, Chicago-based Wm. Wrigley Jr. Co. It is the first time the ADA has permitted its seal to emerge on gum after clearing it for thousands of products since 1930.

The ADA said its independent assessment of the studies verifies those three gums have been shown to help avoid cavities, lessen plaque acid and strengthen teeth.

It said studies presented by Wrigley showed that chewing those gum products for 20 minutes after meals increases saliva production.

Saliva, the ADA said, helps neutralize and clean away plaque acid and bathes the teeth in minerals such as calcium, phosphate and fluoride, which make stronger tooth enamel and help put a stop to cavities.

Clifford Whall, director of the ADA seal of acceptance program, said its council on scientific affairs found the studies, which focused exclusively on Wrigley products, had followed scientific principles. He said, "The council has concluded that there are some health benefits to chewing these products three times a day for 20 minutes."

Wrigley paid $36,000 to put forward its evaluation material. The ADA also said Wrigley spends $35,000 to $45,000 in exhibit space at its annual meeting, advertising in its publications and on other sponsorships. It moreover pays $25,000 to help sponsor an ADA health-screening program.

Consumers advocate Peter Lurie said the dental association ought to test other products prior to issuing such a seal, with the system appearing to be bias in support of large companies.